feat: newgrounds support

[hyperdefined]

A WIP pull request for adding Newgrounds support, from #620.
Would love some help with this, never worked with cobalt source before or Javascript.

Links supported:

• https://www.newgrounds.com/portal/view/938050
• https://www.newgrounds.com/audio/listen/500476

Here is what's missing:

• Video downloads don't have the correct file name, extension is undefined.
• Audio links work, but the filename is incorrect (downloads as newgrounds_id.undefined)
• Audio files do not have metadata attached, not sure how to do this currently.

[ihatespawn]

https://www.newgrounds.com/audio/listen/1343831 doesn't work

{
	"status": "error",
	"text": "newgrounds is supported, but something is wrong with your link. maybe you didn't copy it fully?"
}

[hyperdefined]

everything seems to be good, if anyone wants to take a look

[ihatespawn]

lgtm

[ihatespawn]

https://github.com/imputnet/cobalt/blob/current/CONTRIBUTING.md#clean-commit-messages

[ihatespawn]

deepsource fixes

[hyperdefined]

Was not aware about rebasing, I'll fix that for the future.

To fix the ugly messages, I can redo this PR if needed.

[ihatespawn]

i don't think you need to redo the pr, i didn't see any prs be rejected because of that

[hyperdefined]

ok that did not work, thanks github for the merge 👍

[wukko]

but why

[hyperdefined]

going to redo this, the branch is out of date and I don't want all the ugly testing commits in it